Remove v8 source dependency, enable more compiler warnings

dart/dart.gyp

 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 {
   'targets': [
     {
       'target_name': 'most',
       'type': 'none',
       'dependencies': [
@@ skipping 92 matching lines @@
             'tools/upload_sdk.py',
             '<(PRODUCT_DIR)/dart-sdk'
           ],
         },
       ],
     },
     {
       'target_name': 'dart2js',
       'type': 'none',
       'dependencies': [
-        'third_party/v8/src/d8.gyp:d8',
         'utils/compiler/compiler.gyp:dart2js',
       ],
     },
     {
       'target_name': 'analyzer',
       'type': 'none',
       'dependencies': [
         'editor/analyzer.gyp:analyzer',
       ],
     },
@@ skipping 19 matching lines @@
         'packages',
       ],
     },
     {
       # This is the target that is built on the dart2js build bots.
       # It must depend on anything that is required by the dart2js
       # test suites.
       'target_name': 'dart2js_bot',
       'type': 'none',
       'dependencies': [
-        'third_party/v8/src/d8.gyp:d8',
         'create_sdk',
         'packages',
       ],
     },
     {
       'target_name': 'api_docs',
       'type': 'none',
       'dependencies': [
         'utils/apidoc/apidoc.gyp:api_docs',
       ],
@@ skipping 53 matching lines @@
     },
     {
       'target_name': 'packages',
       'type': 'none',
       'dependencies': [
         'pkg/pkg.gyp:pkg_packages',
       ],
     },
   ],
 }